Amino acid sequence of silkworm (Bombyx mori) hemolymph antitrypsin deduced from its cDNA nucleotide sequence: confirmation of its homology with serpins.
A cDNA clone of silkworm (Bombyx mori) larval hemolymph antitrypsin (sw-AT) has been isolated from a fat body cDNA library. The cDNA has an open reading frame which codes a 392-amino acid residue polypeptide comprising a 16-residue signal peptide and a 376-residue mature sw-AT of Mr 41,805. The reactive site of sw-AT for inhibition of bovine trypsin [Sasaki, T. et al. (1987) J. Biochem. 102, 433-441] was identified as Lys343-Val344. Alignment of the sw-AT amino acid sequence with those of 11 members of the serpin superfamily of proteins clearly confirmed the homology of sw-AT with serpins. The amino acid sequence of sw-AT is 56% identical with that of the proteinase inhibitor from a lepidopteron, Manduca sexta [Kanost, M.R. et al. (1989) J. Biol. Chem. 264, 965-972], but the sequence around the reactive site shows no homology and the inhibitory specificity for proteinases is very different.
Takagi
H
H
Department of Food Science, School of Agriculture, Nagoya University, Aichi.
Narumi
H
H
Nakamura
K
K
Sasaki
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry*; D015698:Genomic Library; D006458:Hemolymph / Q000737:chemistry*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012333:RNA, Messenger / Q000737:chemistry; D012689:Sequence Homology, Nucleic Acid; D015843:Serpins / Q000235:genetics*; D012995:Solubility; D014361:Trypsin Inhibitors / Q000235:genetics*
D012333:RNA, Messenger; D015843:Serpins; D014361:Trypsin Inhibitors; D004247:DNA